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View Full Version : 3 phase for smaller machines.



J Tiers
11-12-2004, 12:13 AM
At the moment, Surplus Center has several sizes of 3phase motors for sale.

One of particular interest to flat-belt machines like small Logan is the 1/3 HP for $19.

Yeah, I'm about to get flamed about how small and useless 1/3 HP is.

Well, let me say this about that....

The 1" flat belt on mine won't transmit much more than that, in direct drive. The cone pulley forces slow belt speed, and so if you do the math, for single-ply belting at sensible tensions, about 1/3 or 1/4 HP is about all you get through it.

I know for a fact that I have NEVER stalled the 1/3 HP single phase motor on it now, but I have slipped the (freshly cleaned, rubber composition) flat belt.

The $18 is competitive with garage sale specials......after shipping its a bit more, but still OK.

Item # 10-1380-A.

And, no of course I am not part of S-C.....but the motor that arrived today looks pretty good...they had 296 left after mine. I happen to have a 1HP to use as a rotary converter.

BillH
11-12-2004, 12:17 AM
Im with you on these small motors, same story with my south bend lathe, everything I have ever done, I never stressed the motor yet, and if I try, the belt slips off. And the lathe has always done what I asked of it. 19$, go for it, hell, maybe I'll buy one too for down the road just for fun.

BillH
11-12-2004, 12:21 AM
http://www.surpluscenter.com/item.asp?UID=2004111122230109&item=10-1380-A&catname=electric
thats the motor? Hmm, one thing that has me wondering now is that its non vented, and has a 30 minute cycle.

Forrest Addy
11-12-2004, 12:57 AM
Jerry, I notice than motor has a 30 minute rating. Will that hurt your application. While we're on the subject, here's a nifty little number from Dealer's Electric for $127:

Item # F1P5, 0.5 HP, 115 input volts single phase, new in carton, make: TECO, Mod. FM50-1P5-C, 230 V three phase output at full 1/2 HP rating.

Oh, none of these in stock. Call them

J Tiers
11-12-2004, 07:56 AM
30 min at full load? REALLY doubtful that will be a problem for lathe usage.

Given that the full power can't get thru the belt anyway, it is likely that the long term average power usage on lathe is well under 50% duty.

Idling current draw maybe , but on OUR little machines, no clutch, motor on use it , finish cut motor off.

This ain't a production shop.....

wierdscience
11-12-2004, 10:09 AM
You don't have any scrapyards nearby?
I usually get small 3~ motors for free,they don't want them you know,too much trouble to clean for scrap.
I got tons and tons at work,we get $5-$10 a hp guaranteed to run.You might shop around locally.
This is why I like wiring a 3~breaker panel to my converter,I can add motors at will.

firbikrhd1
11-12-2004, 12:59 PM
Hi Guys,
I have no input about 3 Phase motors, however, I did want to make those of you who have trouble with your small flat belt lathes aware of something related. I have a 10" Logan that had a leather flat belt and originally gave me similar slipping troubles. I finally purchased a flat belt made of modern materials from a company that makes conveyor belts. The belt isn't rubber, but a composite of some type, and very thin. Now, I can feed enough to slow my 1/2 HP motor down without belt slippage in direct drive. Eventually I plan to install a 3/4 or 1 HP in it's place. If you want to transmit additional power it may be worth checking out.

J Tiers
11-12-2004, 01:47 PM
<font face="Verdana, Arial" size="2">Originally posted by wierdscience:
You don't have any scrapyards nearby?
I usually get small 3~ motors for free,they don't want them you know,too much trouble to clean for scrap.
</font>

Yeah, I can get all the 1HP and up that I want. Small 3phase are rare around here, haven't seen any for some time, since I started looking, in fact.

I just didn't have room for the bigger ones....needed something around the 1/3-1/2 HP to fit so that I don't have to completely re-do the entire motor mounting. This has a S-B motor mount and counter-shaft, and I mounted it fairly close on the stand...diameter is an issue, so is length.

The stock Logan system probably would have fit it, but I don't have it, and like this better anyhow (I have used that clam-shell PITA at the Dad-in-law's).

andypullen
11-12-2004, 03:05 PM
<font face="Verdana, Arial" size="2">Originally posted by wierdscience:
You don't have any scrapyards nearby?
I usually get small 3~ motors for free,they don't want them you know,too much trouble to clean for scrap.
I got tons and tons at work,we get $5-$10 a hp guaranteed to run.You might shop around locally.</font>

I've got a 10hp 3ph motor sitting under the bench at work. (Good for a large convertor) Came off a fan for a ventilating system. Just needs new bearings. Best of all the price....It's considered scrap. When something gets noisy; it gets replaced. I've also got a pair of 1hp 3ph motors that are rated for 835 rpm. They were getting pitched as we had about 20 of them. Apparently, they don't wear out in the application that they were designed for and the boss was getting rid of them. Told me to take them.

Ask around in air conditioning shops. Lots of good motors there...

Andy Pullen

J Tiers
11-12-2004, 11:54 PM
Well, it may be moot.....

When I went to look and start planning out the conversion, I re-read the motor nameplate.....

Advertised on site....230/460V 1.8 / 0.9 A

Order confirmation.....230V 1725 rpm

Shipped....200V only, 2.3A

With a service factor 1.0, and 30 min rating, it ain't gonna fly on 230V.

I have not yet heard when I will get my call tag and when they will ship the right one.

ibewgypsie
11-13-2004, 12:05 AM
http://img.photobucket.com/albums/v85/ibewgypsie/Dscn0653.jpg

What about this one? WEG. Brand new. 10$ and shipping.

I'd give it to you but I have partners who don't have friends..

David

Don Clement
11-13-2004, 12:12 AM
I got a 5 hp 3~ at the dump for $5. It made a good rotary converter for the 3hp. 3~ motors have no wearing parts but the bearings. There is no electrical connection to the rotating part, only magnetic induction from the rotating field. Tesla’s inventions of the 3~ motor and the complete 3~ system are some of the most useful of all time. Perhaps only Marconi’s invention of wireless communication is more useful…wait a minute… Tesla was given the credit for wireless also.

Don Clement
Running Springs, California

J Tiers
11-15-2004, 10:58 PM
WEll, they are sending me a return tag, AND a correct item.

We will see what actually happens.